This is a personal account of the development of the programming language CPL in the early 1960s by a joint team from the University Mathematical Laboratory at Cambridge and the Institute of Computer Science in London. The project was designed to develop a language that would be suitable for all computer applications, scientific or otherwise, would efficiently exploit the immense power of the Ferranti Atlas, would be easy to use, and above all, would exhibit regularity in its form and facilities. Although it failed to achieve all these aspirations, the project did lay important groundwork by establishing some of the basic principles that underlie today's languages and directly led to the development of the BCPL, B, and ultimately C programming languages.